A simulator is a device that simulates a particular experience as realistically as possible. For example, a flight simulator simulates the experience of flying an aircraft, such as an airplane or helicopter. A vehicle driver simulator attempts to create the experience of driving a vehicle over streets or off-road terrains. Simulators typically use display systems to create a field of view displaying what the user might see if the user were actually flying an aircraft or driving a vehicle. Simulators may also provide simulated controls and steering devices associated with the particular aircraft or vehicle, and/or added motion to simulate movement of the aircraft or vehicle.
The visual systems currently in use in simulators were developed for use with four by three (4:3) aspect ratio cathode ray tube (CRT) projectors. However, currently available simulators do not fully exploit the recent advances in visual display technology, such as fixed matrix digital projectors in general, and especially High Definition Television (HDTV) format fixed matrix projectors with wide aspect ratios, such as, without limitation, sixteen by nine (16:9) aspect ratio format. Also, the modern fixed matrix projectors do not have the ability for image scaling without the loss of image resolution since the image source is made up of a mechanically fixed array of image sources instead of a continuous image surface, as with a CRT projector.
In addition, because the shape of the flat screen segments used to tessellate an arrangement of rear projection screens around the eye-point in currently available simulators were designed for four by three (4:3) aspect ratio projectors, the resulting display systems are poorly suited to the use of wide aspect ratios typically used in high definition systems.
For simulation display purposes, users have assumed a goal of providing eye-limited visual performance. Existing display systems have typically used arrangements of flat rear projection screens or dome shaped rear projection screens, neither of which are optimum for creating an eye-limited wide field of view display with constant vertical resolution from the eye-point. In other words, existing display system screens are not capable of providing an eye-limited full field of view display for simulators, such as aircrew training systems.
Pilot training for high performance aircraft has usually required two training devices, one for initial pilot training and one for weapons and tactics training. The initial pilot training system requires a high fidelity cockpit and control law simulation with a motion base for proprioceptive cueing but only a rudimentary visual system. Tactical training devices would have high fidelity weapons systems models and visual systems that are typically not compatible with motion. Tactical training devices may also be networked with other devices in the same facility to allow multi-ship training. There is a need for a pilot training device with a wide field of view, high fidelity visual system that is compatible with motion, yet is small enough so that multiple devices can be installed in the same facility. The visual system for such a device must allow the use of a high fidelity representation of the actual aircraft cockpit. In order to prevent shadowing of projected images by a trainer cockpit structure or by the pilot trainee, cross-cockpit collimated displays or front projected domes have previously been used. Collimated displays, however, are too limited in field of view for tactical aircraft and front projected domes have to be relatively large to prevent shadowing, which limits the number of trainers that can be placed in a single facility with limited space. On the other hand, use of a rear-projected circular dome mitigates the cockpit shadowing, but requires a relatively large number of projectors due to image distortion as a projected image wraps around the outside curvature of the circular dome.
There are only two types of high fidelity visual systems that have been used on motion base simulators. One uses the cross-cockpit collimated display system and the other uses the front projected circular dome display system. The cross-cockpit collimated display was designed for transport aircraft, with side-by-side seated pilots, and does not have the appropriate field of view for a fast jet or attack helicopter. This type of a display system has been used on a limited basis for these applications by extending vertical and horizontal fields of view. Vertical field of view is generally restricted to 60 degrees. Achieving a horizontal field of view beyond approximately 200 degrees becomes relatively expensive. The front projected dome has been used for fixed wing fighter and attack helicopter simulators but because the projectors must be on the same side of the screen as the cockpit, the projectors were placed in non-ideal locations that compromise resolution uniformity and projector efficiency. In addition, in order to prevent shadowing of the projected image, either the dome was made large or portions of the aircraft structure, such as the physical representation attack helicopter overhead cockpit structure was removed. This structure provides visual spatial references that are very important for initial pilot training. Furthermore, both the cross cockpit collimated and front projected dome displays require large facilities with high ceilings and are not compatible with the types of facilities used for tactical training devices. It is with respect to these and other considerations that the disclosure herein is presented.